Process for making pneumatic tires



Nov. 6, 1928.

B. DE MATTIA PROCESS FOR MAKING PNEUMATIC TIRES 2 Sheets-Sheet FiledSept. 29, 1925 INVENTOR fiarzfialtifleflall ATTORNEYS Nov. 6, 1928.

B. DE MATTIA PROCESS FOR MAKING PNEUMATIC TIRES Filed se t. 29, 1925 2Sheets-Sheet 2 INVENTOR ATTORNEYS hraold je WITNESSES I in' crosssection to the tire.

Patented Nov. 6, 1928.

UNITED STATES PATENT OFFICE.

BARTHOLD DE MATTIA, OF CLIFTON, NEW JERSEY, AS SIGNOR, BY MESNE ASSIGN-MENTS, TO NATIONAL RUBBER MACHINERY COMPANY, 0F AKRON, OHIO, A

PORATION or OHIO.

COR-

rnocnss non MAKING PNEUMATIC TIRES.

Application med September 29, 1925. Serial No. 59,394.

The present invention relates to a'process for making pneumatic tires.More partic ularly the invention relates to the manufac- The presentinvention may be said to con sist of a process comprising the followingsteps: First. Building'up a shoe or casing with the greater part of itsside walls above the beaded edges angularly disposed or inclined withrelation to each other with the beaded edges spread apart; Second.Bring} ing the beaded edges of the green or unvulcanized tire towardeach other about a form, thus impartinga substantially circular shapeThird. Vulcanizing the tire while held in its substantially circularshape in cross section.

The present invention is illustrated in the accompanying drawing inwhich 1 Fig. 1 shows in cross section a shoeor casing. as built upbefore shaping and vulcanizing.

Fig. 2 shows in cross section an explanatory diagrammatic view.

Fig. 8 shows in cross section the shoe or casing removed from the coreupon which it. was built up, and wltb an inflatable core or air bag asit is called, shown in dotted lines, inserted therein.

Fig. l shows in cross section the shoe or casing with the beaded edgesbrought together about the inflatable core or air bag, or substantiallythe standard shape in cross section.

Fig. 5 shows in cross section the shoe or casing and the inflatable coreor air enclosed within vulcanizing molds for the usual process ofvulcanization.

Similar reference characters will be employed throughout thespecification and drawing to designate corresponding parts.

As is well known to those skilled in this art, shoes or casings forpneumatic tires are circular in cross sectionor of a shape corresponding to the shape in cross section of'a standard tire shoe orcasing, with the walls abovethe beaded edges curved, both above andbelow an imaginary horizontal line cutting a cross section of the shoeor casing at the axis thereof, and with the beads or beaded edgesclosely approximating each other.

Because of this substantially circular cross sectional shape it is quitedifficult to shape, form and stitch the fabric from which the shoes orcasings are made, so as to dispose of the "fullness developed as andincident to shaping the fabric about thecore above the aforesaidimaginary horizontal line, such shaping of the shoe or casing developingconsiderable fullness below the aforesaid imaginary horizontal line,which of necessity erly forming the beaded edges.

. In such an operation as heretofore carried. out, the wall of the shoeorcasing above the beaded edges define arcs of a circle approximatingthe required circular shape in cross section of the standard tire,whereas in the improved process which will now be 'described and which,as hereinbefore stated,

' each other and towards the crown or. tread.

By thus forming or building up the shoe or casing, the fabric from whichit is made can be conformed and laid upon the shaping or moldingsurfaces of the core with very little effort, producing a minimum amountof fullness at or adjacent the beaded edges which maybe readily and withlittle effort pressed and laid in position along and around,theflbeadediedges.without employing an extensive"fstitchingl operation.zaAfter the shoe or casing has been thus formed, it is removed from thecore and by a suitable device,such- -as an" inflatable-core or airbag,and the usual vulcanizing melds given a substantially circular shape incross section with the beaded edges closely approximating each other,thus changingthe sh'ape in cross section and producing .the standardtire shape in cross section, after which it is vulcanized in the usualmanner.

.Inf the {drawiifig, j the shoe I or casing? 1: :is.

.. biiilt. :up; ofalayers. ofQ-f'a-b'ricconstituting the sidewalls; 2,beaded edges 3.1and. a tread .sur-

, liface- 4 .inflthe v.usu'al manner, except :that .as jndic'atdrinligs. 1,2 and arse, beaded edges I3.are.spread apartforsome,tancear'idlthat l thev walls 2Qabove. the; beaded- .edges fffrom a.point iclosely'approximating the beaded [ledges are. inclined.toivardsieach other; and niergefinto' ,the curved .icrown or tread (A.'jjThe tire bl-ankias, thus formedrinay. be'gs'aid to, be. substantiallytriangular in. cross sec tion,the base of the triangle beinganinraginary line connectingthe beaded edges. ;'The 30 tire'thusgformedand as re1noved'.-fronithe core upon which it Was'biiilts-is'placdupon a. shaping core, whichanay consist of the usual and wellknowriiiifi'atable core jor .air

' bag 5, see,d'ott-ed,lines (Thereafter, was in'dicatedin-Figja, thebeaded edges 3 are forced towards each, other and'the walls "'2 causedto. approximate in shape the shap- \ing core or air bag,.-af1dthe wholeassemblageislis;placedlwithin asuit-able Vulcan- 40 flizing' apparatus,such as'the mold 6,-and'the "air bag being'iiifl'ated in the usualmanner, the shoe or casing. iscaused to conform to the shape ofthe mold,and while-held under 1 pressure it is vulcanized in the usu'al manner.The vulcanizing inold comprises the usualbead support ng rings 7 andthem- "flatable shaping core or air bagis provided ith the-usual valvemechanism .8 by means of which ainmay. beadniitted' thereto.

and with the diameter at" the .crown or tread piortion substantiallythat" of the completed tire, and of course withthe beaded edgesexactlyfthe diameter required for the .'.size .of

' tir egand tof'fit a" rim of a 'given size. In building up a tire thefabric, is; generally .cut :on' the biaswith the threads extendingldi-.agonally, those. of adjacent superimposed i'l ayers crossingeacho'thert at substantially a (SO-right angle. The mesh "or threadsim'- mediately. acent a central circumferential *lineextending aboutthe-crown ortread are "opened up or spread I in conforming-"the 'fabric'to the. shaping surface of: the; core.

In theold process a considerable-fiillness is I The tire islbui'lt'up'infthe usual; manner.

point corresponding to the widest diameter I ,(see Fig.2), sothat thewalls of the tire froni'the beads tothe tread are substantially fiatvand. inclinedwith. relation .to. each other otherwise. conformed to theunderfcurved ksurfaces: of the coreas in 'theold, process. .LAtirethusl' formed is caused to assume .ap proximately. tl1e.sl1apeincrosssec'tion of. a standard tir,e,. by movingrfthe Ebeadd edges-toW.ards ,each other. .soth'at. they will pass from 'theouter side ofvertical lines struck from the widest part of the core to-the inner..-..'.side of .such lines. Such movement of the beaded edgesautomatically causes the awall of the tirebelow'the horizontalfline toconform to. the under curved surfaces and. to assumesubstantially theshape desired in thefinished tire,- and this is accomplished Without thenecessity of taking upsthe full- .ness developed inlthe'sever'al' layersas the tire is built. up. It will be observed also "that-as thebeadsori-beaded edges'are of a fixed diameter and the tread also being of -asubstantiallypfixed diameterfthe wall of the tire between theseypoints:will be caused to bulgeor changefrom an outwardly vin- .clinedstraightlinez to an inwardly curved line. as the beads pass from theouterv 'side'of the vertical" lines to (the innerlsiddtherebf. Thispreliminary shaping approirini'atesfthat of the standard tiregand thetrue: shape of the standardtire is eifectedor produced by the inflationofthe air bagwhichjpresses the wail of the tire 'ag'ainst'the moldingsurface of.the vulcanizing mold. p c Having? described my invention, I.cl'aim 1..lheprocess ofmanufacturing apnea .matic tire'which consists.in building the unvulcanized'tire to .conformin "cross section to aninverted letterV the tread defining the apex and thebezidededgesdelimiting the tipsof the V, in forcing. the beadecl..edgestoward each other,';in expanding the tire .;unifor1nly from the insidethereofto impart .toit its ultimate shape and. siz'eyan d'in retainingthe" tire"thus"stretched duringvuL,

canization thereof.

2 "The process of .manufacturing pneuma'tic tirewhich consistsinapplying agplu- "rality of-plies oftire material and a'pair ofbead-rings to a"'core'of substantially tl'lr angular" cross-section,stitching the edges of thusfthere-yis'little 0r\.no.1fu]lness -which-.is required to-beplaited, pressed, stitched and on I the respectiveplies to said bead-rings to form a tire blank, removing the so-formedtire blank from the building core, and modifying its shape by applyingit to a core of 5 substantially circular cross-section.

3. The process of manufacturing a pneumatic tire which consists inapplying a plurality of plies of tire material and a pair of bead-ringsto a building core of substantially triangular cross-section, stitchingthe 1 edges of the respective plies to said beadrings, removing theso-formed tire blank from the building core, applying the tire blank toan expansible core, modifying the shape of the tire blank by expandingsaid expansible core, and vulcanizing the blank in such modified shape.

BARTHOLD DE MATTIA.

